If AMC's Better Call Saul is a car trip and the destination is Saul Goodman, it often feels as if fans and critics alike are piled into the backseat, relentlessly peppering the drivers — creators Peter Gould and Vince Gilligan, plus their spectacular writing and directing team — with variations on "Are we there yet? Are we there yet?"

Monday's finale seemed to push us one step closer, with Jimmy McGill (Bob Odenkirk) on the verge of getting his legal license back and making the announcement that he intends to practice under a different name.

To get there, he had to con an appeals board with a heartbreaking story about his deceased brother, an act which also left him conning poor Kim (Rhea Seehorn), who wanted to believe Jimmy had changed, only to be left with a not-so-reassuring, season-ending "S'all good, man." See what he did there?

With only 10 episodes apiece, Better Call Saul seasons always feel too short, so the finale marks a good opportunity to get on the phone with Peter Gould to talk about where Jimmy is in his journey, how his concerns for Kim have changed and whether there have been conversations about when or if the show, already renewed for a fifth season, will be setting an official end point.

Gould also discusses how this season's two appearances from David Costabile reflect on Gale's ongoing importance to the series, and how much stock we should put in the business card Jimmy/Saul gave to Francesca in the brief flash forward into the Breaking Bad timeline.

It definitely felt like you'd been saving up for that final line. How long did you have that as a thing you were shooting for?

I don't know about the last line, but I think what we had at midseason was the idea of Jimmy using Chuck's death to get reinstated, using the fact that his brother has died as a piece of insincere manipulation. The key part of the idea was that Kim and hopefully the audience too are taken in by Jimmy's act. That's what we were hoping to build toward. The "S'all good, man" that Bob does at the end was sort of the icing on the cake.

Was there consideration to Jimmy having one last Chuck-induced respite where he was able to sincerely find that scrap of decency through his brother's memory?

Boy, I don't know that we've seen the end of Decent Jimmy. We still haven't fully tested who this guy is right now. He's on a dark journey, and I don't think he's going to take a lot of steps backwards, but I think like all human journeys, it's gonna be a little zig-zag-y and hopefully unpredictable. I wouldn't rule out the idea that there are still some decent actions yet to come. Having said that, Jimmy as we know him at the end of season four would do a lot of things that the Jimmy who we met at the beginning of the series would not have done.

Is the question that people keep asking over and over again, and that I'm sure I've asked a half-dozen people a half-dozen times, the "Is he Saul yet?" question, a frustrating one? Does it seem reductive, given the series you've actually been making for four years?

It's not a reductive question! It's a question we ask ourselves in the writers room all the time. We're always asking ourselves, "What does it mean to be Saul Goodman?" I can't help but see it, just because of the way this show and Breaking Bad were structured and the way we thought about them. I think it's a moral downfall. It's a moral journey. The question for us is not "What is he calling himself?" or "What is he wearing?" or "What kind of TV commercials is he making?" The question is "What's he willing to do?" and "Who's he willing to hurt to get the things that he wants?" and "Where is he as a human being?" It's interesting, because I think we now, at the end of season four, understand the appeal of the moral descent, or the dark side, like they say in Star Wars. I think we understand it a lot better. I understand that a lot of it comes from hurt and pain and rage. Like Bob sometimes says, Saul Goodman is a choice. It's a bad choice. It's a punk-rock choice. But it is a choice.

I think we've always known that Saul and Gene represented these tragic destinations for Jimmy. Has your sense of Kim's destination and what the most tragic conclusion for her would be changed?

I've gotten much more invested in Kim than I was when we started. I don't think any of us understood how important Kim Wexler is to the show and is to Jimmy when we started out. As the show goes on, she becomes more and more important to all of us. All I can say is that we certainly talk about all the different fates that you can imagine. I like to think that we have discussed at least in passing almost every option that we can conceive, but having said that, I'm just worried about her. You can feel how important Jimmy is to her, what a problem solver she is and how good she is at saving people, and it just feels like this may be…a very bad spot for her.

But has your sense of what the bad spot would be changed? When we started, there was this sense that a Jimmy/Kim breakup would be very sad, that that would be the saddest thing we could think of and perhaps the worst fate for either of them. I don't think I feel that way anymore, and it's fascinating how the nightmare scenario for Kim has shifted over the years.

The nightmare scenario is definitely not that she breaks up with Jimmy. The nightmare scenario is that she doesn't. We all love these two together, and it's interesting because the fact that this is a prequel really does give us different notes to play. Obviously not everyone who watches the show has watched Breaking Bad, but it gives us a different feeling when we see the two of them together, just the fact that there's this context around the scenes, that you know this is not going to last. Having said that, we're all mortal, and nothing lasts forever. I agree with you. Sometimes I hear people say, "Maybe Kim is still in his life when he's Saul," and I'm not going to say it's impossible, but in some ways that seems more tragic, or as tragic, as Jimmy becoming Saul Goodman.

When it comes to Nacho [Michael Mando] and introducing Lalo [Tony Dalton] this season, how surprised have you been by how much you've been able to milk from one 45-second scene from Breaking Bad?

(Laughs) Oh my God! I would never have believed what would grow out of that episode of Breaking Bad, the first Saul Goodman episode. The fact that we're all still working together, and we're working together on this particular character, is shocking. Now, as for what Saul Goodman says when Walt and Jesse have him at gunpoint? No, I would have never believed that we would be making a storyline based on that. Having said that, it was important to us, because you really don't find out that much about Saul Goodman in the course of Breaking Bad. You don't even find out what his real first name is. Everything that happens in Breaking Bad with Saul is very much centered on Walt and Jesse, so any little clue about what was going on in his life before they arrived or while they're around, all those little clues are things that we think about an awful lot.

Saul Goodman is, as we know, not the most sincere character. Have you guys been forced to take some things he said in Breaking Bad that, in the moment were meant insincerely, as truth? Certainly the first scene with Jesse and Walt could be read as stalling or misdirecting, yet it has turned out, at least so far as we know, that it was all true.

It's interesting that you think he might be stalling, because I take it very seriously. But you're right that that is always the question. Saul Goodman told a lot of tales about his previous life in the course of Breaking Bad, and it's so fun when those things turn out to be true. For instance, "I once fooled a woman into thinking I was Kevin Costner. She believed it because I believed it." It was so much fun to actually see that that was the truth back in season one. I don't know if we're ever going to be able to follow up on every single thing that he said. We'll do our best, though.

Speaking of things Saul said that need following up on, you guys made that detour into the Breaking Bad timeline earlier this season, and the thing that really stuck with me was Saul giving Francesca the card and telling her to call his lawyer and "Tell 'em Jimmy sent you." Is the identity of that lawyer something I want to have latched onto?

You know, we put it out there. I guess we really ought to pay it off. (Laughs) I can tell you that these things often seem like a great idea when you're breaking a scene or you're writing a scene, and then you wake up after the season's finished shooting and posting and you go, "Wait a minute. We have to follow up on this?" The basic, fundamental example that we always go back to is the machine gun in the trunk in Breaking Bad. I can't tell you how many times Vince said, in the writers room on Breaking Bad, "Oh, think of all the wonderful things we could do if we hadn't put that machine gun in the trunk." I don't think the card that Saul gives to Francesca falls quite in that category, but we've really done our best in the past to pay off things like that, so I'm gonna hope that we're gonna be able to pay that off before we're done.

The introduction of Gale in multiple episodes this season was fun, but how concretely do you guys have in your heads what his role is in the upcoming arc of this show? And how much of that is narratively driven and how much is Billions-availability driven?

We were so damn lucky that David Costabile was able to zip over to Albuquerque to do his two scenes. We're gonna hope we can work it out, because we love David, and we love Gale. Gale is actually a pretty important character, not just because he's an excellent meth cook and designer of the SuperLab, but also because he has a very different relationship with Gustavo Fring. When David is working with Giancarlo [Esposito], I just think there's a certain magic between these two guys, between these two characters, and it goes to a side of Gus Fring that we really don't see anywhere else. So I'm really hoping that we can have David back. The producers of Billions are wonderful guys. Andrew Ross Sorkin, who's one of the creators of the show, wrote the book that I adapted for HBO, Too Big to Fail, so I'm gonna take responsibility for getting Andrew into show business, and I'm gonna hope we can work something out.

Put a different way, then: Is Gale mandatory to the story you need to tell, or is he a luxury item?

I don't know if I can answer that! It's a deep question, and I'll be able to give you an answer in about 14 months, I think.

Last year you had to sweat out the renewal a little bit, not that it was necessarily in doubt, but you had to wait until after the season was over before it could be formalized. This year you got the fifth season renewal early, and I was wondering if that extra time has given you additional perspective when you look at the finite lifespan of the series. It has to be finite, right?

The show is finite, and, for better or for worse, we're telling a story with a beginning and a middle and an end, and it really feels like we're closer to the end than to the beginning. I don't know how many more seasons we've got for sure, and obviously some of that is a question of how much more story there is to tell and some of it is hopefully enough people watch to continue having it as a going concern. We're relying very much on the fans to keep us on, and we'll have to see. Before season five is over, I think we'll have a very clear idea of how much further we've got to go.

But there hasn't been the conversation of, "Okay, Sony and AMC, we can do this in 16 more episodes" or "Okay, we need 20 more episodes to finish this" or whatever?

I'll be honest with you: There's been a little bit of conversation, and I don't want to be coy about it, because AMC and Sony have been incredibly supportive. What they've really said is that they want us to take the lead and figure out how many more episodes there are. So that's something we're working on!